Review of gender identity data harmonised standard

Policy details

Metadata item Details
Publication date:15 December 2022
Owner:GSS Harmonisation Team
Who this is for:Users and producers of statistics
Type:Harmonisation standards and guidance

Harmonised standards and guidance

The Government Statistical Service (GSS) Harmonisation team are based in the Office for National Statistics (ONS). The team supports harmonisation of data across the UK. This involves providing bespoke advice and harmonised standards and guidance about how data on different topic areas are collected and presented. The standards and guidance are designed to improve the consistency, coherence, and comparability of statistics.

Producers of statistics use these harmonised standards as a starting point in their data collection process. By using harmonised standards they can:

Harmonised standards also allow people to effectively and accurately compare data that has been collected across different datasets. This means we can more easily understand what that data does, and does not, tell us. This ensures that statistics are being used to their full effect for the public good.

The current gender identity data harmonised standard was published in July 2020 and created using research and testing undertaken for Census 2021 in England and Wales. This standard has been developed for respondents aged 16 and over. In Scotland’s Census 2022 a question was asked on trans status and history.

The harmonised standard was published as ‘under development’. This means there is a need for further research to develop the standard. This review:

  • summarises reasons for conducting this review
  • summarises the strengths and weaknesses of the current standard
  • sets out future work that we plan to do to move the standard from ‘under development’ to ‘final’
  • sets out timelines for this future work

This review of the current harmonised standard fulfils a commitment we made when publishing our GSS Harmonisation Team Workplan in February 2022. The purpose of conducting this review was to evaluate how the current standard has been used, and to use feedback we received to help guide future work to move the standard from ‘under development’ to ‘final’.

As part of this review, we have worked with a variety of government survey owners to gather feedback on their experience of using the current standard. This included asking about areas where these stakeholders feel the standard could be improved.

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Reasons for this review

There is a growing need for information on gender identity. The Inclusive Data Task Force recommendations report shows the importance of harmonised standards that consider changing social norms and respondent and user needs. This standard is under development and was published in July 2020. This review provides us with an opportunity to demonstrate how the current standard has been used over the last two years and evaluate its performance.

In addition, our current standard was designed for self-completion modes only and does not contain guidance for interviewer-led modes. To start to address the growing need we looked at how the standard has been used and investigated its strengths and weaknesses.

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The current harmonised question

Question in the current standard

In the current standard, the gender identity question has two parts.

Part 1

Whether a person’s gender identity is the same or different from their sex registered at birth – captured via the ‘Yes’ or ‘No’ response options.

Part 2

How people wish to self-describe their gender identity – captured via the free-text box.

English language self-complete question


Is the gender you identify with the same as your sex registered at birth?

Response options

  • Yes
  • No, enter gender identity
  • Prefer not to say

Welsh language self-complete question


Ydy’r rhywedd rydych chi’n uniaethu ag ef yr un peth â’r rhyw a gofrestrwyd pan gawsoch chi eich geni?

Response options

  • Ydy
  • Nac ydy, nodwch eich hunaniaeth o ran rhywedd
  • Mae’n well gen i beidio â dweud

Scotland’s Census trans status and history question

The National Records of Scotland (NRS) asked a question on trans status and history in their 2022 Census.


Do you consider yourself to be trans, or have a trans history?

Information about the question

This question is voluntary

Answer only if you are aged 16 or over

Trans is a term used to describe people whose gender is not the same as the sex they were registered at birth

Response options

Tick one box only

  • No
  • Yes, please describe your trans status (for example, non-binary, trans man, trans woman)

The Chief Statistician for Scotland also published guidance on the collection of gender identity data.

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Surveys that have used the current standard

The following surveys have used the current standard:

  • England and Wales 2021 Census (Office for National Statistics)
  • Crime Survey for England and Wales (Office for National Statistics)
  • Labour Force Survey (Northern Ireland Statistics and Research Agency)
  • Continuous Household survey (Northern Ireland Statistics and Research Agency)
  • Civil Service People Survey (Civil service)
  • NHS GP Patient survey (NHS England)
  • Safe Community Survey (Northern Ireland Statistics and Research Agency and Department for Justice)

We would be keen to hear about other surveys where the standard has been used. Please contact and let us know.

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The methods we used to do this review

To review the gender identity standard, we undertook two exercises.

Exercise 1: Conducted a survey of data collectors and processors

The GSS Harmonisation team have an ongoing survey of data collectors and processors. This gathers information on surveys that use harmonised standards and includes information such as data collection modes and capabilities. This survey captures information across our harmonised standards and provides us with general information, such as ability to use free text.

We used information from the survey up to July 2022. This provided a sample of 43 respondents from a range of organisation types, including central government departments, devolved administrations, and the private sector. There was a good balance between data collectors and processors in the sample. 40% of respondents were from devolved nations, which represents a large proportion of the sample. To gather this sample, we:

  • identified key stakeholders across UK government, devolved nations, and the private sector
  • selected relevant data collectors and data processors from the list of stakeholders to be contacted to fill in the survey
  • contacted GSS Harmonisation champions (representatives who have an interest in Harmonisation across many different departments) to help identify additional data collectors and data processors that use the harmonised standards
  • ​conducted an implementation review to identify surveys that use harmonised standards
  • contacted producers of official statistics that use harmonised standards and additional contacts identified through follow up stakeholder engagement

Exercise 2: Spoke to government survey owners who have used the current standard

In addition to the ongoing survey, we also targeted survey owners within ONS and other government departments who we knew currently ask a gender identity question. We asked for their experience of using the current gender identity data standard. We also asked them to gather and provide feedback on the gender identity question from respondents, interviewers (if applicable) and data users of their surveys. This information would be used to ensure we had feedback from as many perspectives as possible.

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Strengths and weaknesses of the current standard

Known weaknesses of the current standard

The ability to process free-text responses

The current standard question offers participants the opportunity to enter their gender identity in a free text box if they answer “No” to the gender identity question. While our survey found that 55% of data collectors reported they were able to provide free-text options, only 24% of data processors said they were able to process a large amount of free text.

Additionally, some of the survey owners who have implemented the current standard reported that they do not have the system capabilities or subject knowledge to process the free text gender identity data.

Both of these issues present a risk to data quality and coherence and may affect comparability of data between sources.

We also know that free-text options can present issues with disclosure control when there are small numbers of responses in each category. Due to the sensitive nature of the data, some responses may need to be supressed from output files if there is an issue around cases becoming identifiable.

Mode inconsistencies

The current standard was designed for self-completion modes. This means that the standard does not contain guidance for how interviewers should ask respondents about their gender identity if they answered “No” when asked whether their gender identity is the same as their sex registered at birth. We found this meant survey owners would use different wording to ask respondents if their gender identity is the same as their sex registered at birth. We also found survey owners would present the “prefer not to say” option differently. Both of these variations could affect quality and comparability of data between sources.

Known strengths of the current standard

Comparability with Census 2021 data

The current standard is based on the gender identity question that was included in the 2021 census for England and Wales. This means that data collected using the standard will be broadly comparable with Census 2021 data, but the survey design will also affect comparability. It is important to note that the gender identity question was labelled as voluntary in Census 2021, whereas in the current standard a “prefer not to say” option is suggested.

Broadly comparable with Scotland’s Census

The current standard and Census 2021 for England and Wales both ask a question on gender identity. However, Scotland’s Census 2022 asks a question on trans status and history. This is because the National Records of Scotland (NRS) identified a user need for data about the trans population during their consultations. Despite these differences in the wording or terminology the Office for National Statistics (ONS), NRS and Scottish Government have agreed that the data collected will be broadly comparable between the two questions. Users should think about these differences if they are making country-wide comparisons of data. They should also use the supporting information provided alongside the data.

Welsh version of gender identity question

Following feedback from the Welsh Language Census Quality assurance group (WLCQAG), we updated our current standard for the Welsh version of the gender identity question. We updated the Welsh version to be the same as the paper form version of the Census 2021, therefore increasing comparability with Census 2021 data.

Usage in Northern Ireland surveys

The Northern Ireland Research Statistics Agency (NISRA) is responsible for the census in Northern Ireland. Because of limited user need for a question on gender identity, NISRA decided not to include a question on gender identity in their 2021 census. But the current standard is now used in several Northern Ireland surveys, including the Labour Force Survey and the Continuous Household Survey. This increases the geographical comparability of gender identity data between the devolved nations.


During question development for the Census 2021 in England and Wales, the acceptability of a gender identity question was investigated. It was found that the term ‘gender identity’ had high acceptability and was easier to understand by respondents than the term trans. It was also found that the write-in option increased acceptability as it enabled people to identify their gender where it is different from sex registered at birth. As the term ‘gender identity’ and the write-in option have been included in the current standard, we can conclude that it has high acceptability. We are aware from stakeholder feedback that ‘gender’ is sometimes preferred to ‘gender identity’.

Continued use of the current standard

Whilst our work on this standard continues, we would encourage users to continue to adopt this standard. This is because it was developed using research and testing that was conducted for Census 2021 in England and Wales. As such, it is likely that this question will still outperform others that did not undergo such a development process.

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User needs

It is important to consider user needs for collecting gender identity data to guide our future work. User needs provide us with information on what is important to different types of users. For example, user needs can help us work out what wording or terminology is most acceptable in a gender identity question.

User needs for the current standard are set out in the gender identity topic report and the question development for Census 2021 in England and Wales. We are aware that these reports were published a few years ago, and we will be considering user needs as part of our ongoing work on the standard.

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Through our research and engagement activities we have found that the current standard for gender identity has clear strengths, which include the comparability with Census 2021 data and broad comparability with data collected by Scotland’s Census 2022. But we have identified issues with the current standard including a lack of guidance for interviewers and the ability to process write-in data.

We will investigate the issues that have been highlighted in this review, and we have set out future research which will be needed to move the standard from ‘under development’ to ‘final’. Once the standard is ‘final’, we will continue to monitor its use.

What happens next

It is clear that we need to provide more guidance for different data collection modes including telephone interviews and face to face interviews. To do this, we will test the question in interviewer-led modes.

We will also be analysing write-in responses to the second part of the gender identity question from Census 2021. We will work with National Records of Scotland (NRS) to understand responses to their trans status and history question in Scotland’s Census.

We will explore the possibility of having a list of gender identities as a closed question. This will be informed by our analysis of Census 2021 data and, if possible, testing with respondents.

We will continue to work with survey owners, and we will gather feedback on the current standard from respondents as part of our ongoing work.

We are planning on doing this work in late 2022 and early 2023. We have updated our GSS Harmonisation Workplan with timelines for each piece of work and will continue to update the workplan as we progress.

It is important to note that the first Census 2021 gender identity data for England and Wales will be published in early 2023. We are also aware that, to date, we have mainly worked with government survey owners for this review. We are planning on speaking to a wider range of stakeholders, including interviewers and respondents, if applicable, throughout the actions set out in our workplan.

We are also planning on looking into and working with administrative data to gather new insights about the topic of gender identity and help to develop our work further.

While this work progresses, we recommend users continue to use the current standard on this topic. But users should think about the issues presented in this review. If you would like to contribute to this work, please contact us, the Harmonisation team at

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Contact us

Government Statistical Service (GSS) Harmonisation Team

If you would like more information about the gender identity data harmonised standard, please contact the Harmonisation team at

You can find more information about Harmonisation on the ‘GSS Harmonisation Support’ webpage.


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